Dishwasher



J. W. JACOBS Dec. 13, 1962 DISHWASHER 2 Sheets-Sheet 2 Filed Sept. 12,1958 INVENIOR. Fly. 2 James W Jacobs BY 5 g z His Attorney United StatesPatent Ofiice 3,i68,877 DISHWASHER James W. Jacobs, Dayton, Ohio,assignor to General Mo- This invention relates to a domestic applianceand more particularly to an improved door construction for a dishwasher.

Two aims of the design engineers in the dishwashing art are to minimizethe amount of steam or vapor which escapes to the area surrounding thedishwasher and to speed the dishwashing cycle. In the current dishwasherdesigns two drying systems are prevalent, one wherein the access doorfor the dishwasher is opened at the beginning of the drying cycle andthe other wherein the door is closed throughout the dishwashing cycle.Maintaining the door in a closed condition provides the advantage ofeliminating the exhaust of steam from the dishwashing chamber andtherefore eliminates the damage arising when condensate forms on therelatively cool surface surrounding the dishwasher. However, the dryingportion of a dishwashing cycle is generally longer in those machinesincorporating the closed dishwashing chamber during drying. It is thepurpose of this invention to include the desirable condensate-freefeatures of a closed drying system in a dishwasher having a doorconstruction designed to expedite the drying cycle.

Accordingly, it is an object of this invention to provide a dishwasherdoor having means for condensing moisture from the air within thedishwashing chamber.

It is also an object of this invention to provide-a door constructionfor a cleaning machine which includes an air cooled condenser.

A more specific object of this invention contemplates the incorporationof a condenser in a dishwasher door having a first conduit incommunication with a dishwashing chamber and a second conduit incommunication with the atmosphere and in heat exchange relationship tosaid first conduit.

It is an additional object of this invention to provide the condenserlast described with a blower system having a single prime mover foractuating an impeller in the first conduit for recirculating vapor froma dishwashing chamber and an impeller in the second conduit forcirculating cooling air from the atmosphere.

It is a further object of this invention to provide a vapor conduit fora door-mounted condenser which will permit gravity flow of condensate tothe sump of a dishwashing chamber for removal to drain.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is a fragmentary side sectional view of a dishwasher suitablefor use with this invention and taken along line 11 of FIGURE 2;

FIGURE 2 is a front elevational view of a dishwasher illustrating thecounterfiow passages of the door-mounted condenser; and

FIGURE 3 is a sectional view of the condenser taken along line 33 ofFIGURE 1.

In accordance with this invention and with reference to FIG. 1, adishwasher having a top wall 12, a rear panel 14 and a base portion 16is adapted to include a dishwashing chamber shown generally at 18. Thedishwashing chamber 18 is a generally box-like receptacle having adepressed bottom defining a sump 20. The

dishwashing chamber 13 has also an access opening 22 in the front wallthereof. Closing the opening 22 is a dishwasher door, shown generally at24. The door 24- may be hinged and latched to the side panels of thedishwasher 10 in any conventional manner and is adapted to be opened bya handle 26. In order to insure a watertight connection between thedishwashing chamber 18 and the door 24, a gasket 28 may be provided andarranged peripherally about the opening 22.

Although this invention is not to be limited to a particular type ofdishwasher, for purposes of illustration the dishwasher 10 is shownprovided with a spray tube 36 rotatably supported at 32 on a bracket 36and at 34 on a spray header 42. During a dishwashing cycle, watercollecting in sump 20 enters a motor-driven pump arrangement, showngenerally at 38, and is recirculated to the spray tube 36 through aconduit 4% the water being so pumped having a swirl imparted to it inthe spray tube inlet header member 42. This swirl imparts a rotationalmovement to the spray tube 39, thereby causing jets of water to issuefrom spray tube ports 44 over the surfaces of the dishes 46 that arecarried in conventional support racks 48. Also within the dishwashingchamber 18 is a heater 5i) which is energized at the conclusion of thewash portion of the cycle to raise the temperature within thedishwashing chamber 18 to dry the dishes therein. It is, of course,possible to energize the heater 50 periodically throughout thedishwashing portion of the cycle to maintain desired higher temperatureswithin the chamber 18. At the conclusion of a dishwashing cycle, a drainsolenoid 52 may be energized to open valve 54 to permit the pump 38 toremove water from the sump 20 to any suitable remote drain. Thedishwashing cycle may be initiated by a start button 56 to energize atimer 58 which thus programs sequentially the desireddishwashing cycle.For additional details on the dishwasher mechanism outlined broadlyhereinabove, reference may be had to the patent to Abresch et al.,2,808,063 issued October 1, 1957.

During the period that water is being circulated from the sump 29 to thespray tube 30, considerable steam is evolved, depending, of course, onthe temperatures of the washing fluids being circulated. When thesurfaces of the dishes and utensils carried by the racks 48 have beensufliciently cleaned and rinsed, it is then desirable to effect a rapiddrying of the cleansed dishes. If the door 2 closing the steam orvapor-filled dishwashing chamber 18 were open, the steam and vapor thusreleased would flow into the surrounding area to condense on the firstcool surface encountered. If this surface happens to be wood, as forinstance, the under side of a countertop overlying a built-indishwasher, a deterioration would be noticed in the surface over aperiod of time. It is therefore desirable to keep the door 24 ciosedduring the drying operation of the dishwashing cycle and the applicanthas provided a novel condenser or dehumidifier to be mounted within thedoor 24 for removing moisture from the vapor within the dishwashingchamber a the dishes are being dried.

A construction is provided for the dishwasher door 24 to permit theinstallation of a heat exchanger, shown generally at dd, therewithin.The door 24 is formed with a front panel 62, a rear panel 64- and aperipheral wall having a top wall portion 66, and a bottom wall portion68. In FIG. 1 the thickness of door 24 has been exaggerated to emphasizethe features of the applicants heat exchanger 69. It should be obviousthat a door of conventional design may be used in accordance with theconcepts of this invention to efiect a condensing arrangement within thedoor. To permit a circulation of the moisture-laden vapor or steamthrough the condenser 60 from the drying chamber 13, a vapor duct orconduit 74 is provided. The duct 74 has a condenser inlet opening 76 anda condenser outlet opening 78 leading from and to the dishwashingchamber 18, respectively. The vapor duct 74 is generally verticallyextending and includes a bottom wall 8% graded generally toward thedishwashing chamber 18 for reasons to be described hereinafter. Withreference to FIG. 3, the vapor duct or conduit 74 is provided with aplurality of heat transfer fins 77 which are generally Z-shaped andspot-Welded as at 82 to the interior sides of duct 74. Thus, vaporentering vapor duct inlet 76 is caused to pass between the heat transferfins 77 as it traverses through the condenser 66 The duct 74 may befabricated of any sheet metal suitable for rapid transfer of heat.

Cooling air is provided the condenser 69 from the atmosphere surroundingthe dishwasher it). A cooling air conduit or duct 84 is included alsobetween the front panel 62 and the rear panel 64 of the dishwasher door24. An inlet 86 to the duct 84 is formed in the bottom wall portion 68of door 24, while an outlet 88 is laterally spaced from said inlet inthe bottom wall 68 to permit the cooling air to return to the atmosphereafter passing over the condenser 60. Surrounding the vapor duct 74 intransverse relationship to heat transfer fins 77 is a second set of heattransfer fins 9%. The fins 90 may be spot-welded to the outside of duct74 in the same manner as were fins 77 welded within the duct. Thecooling air passage or duct 84 is directed over the exterior fins 99 andaround the vapor duct 74 before exhausting from the cooling air outlet83. In this manner the cooling air does not come in contact with the'dishes being washed and sanitary conditions are thus maintained.

The circulating air system utilized in drawing vapor from within thedishwashing chamber 18 and cooling air from the surrounding atmospherewill now be more fully set forth. The cooling air duct 84 is providedwith an enlarged inlet chamber 92 for receiving a fan having a motor 94and a cooling air impeller 96 supported on a motor shaft 98. The motoror power shaft 98 is arranged to project through a bushing or bearing 1%into an outlet header portion 102 of the vapor duct 74. In this locationa second impeller 104 for vapor is carried on the shaft 98. With themotor 94 operating in one direction, the impeller 104 is so formed todraw moisture-laden vapor from the chamber 18 through the vapor ductinlet 76 and into the condenser 60. At the same time impeller 96 drawscooling outside air into duct 84 through inlet 86 and forces this airinto counterflow moisture condensing relationship with the vapor in duct74.

In operation, the dishwasher door 24 may be opened and the racks 48slidarbly removed from the dishwashing chamber 18 to permit loading ofthe dishwasher. When the racks 48 have been returned to their positionwithin the dishwashing chamber 18, the door 24 is closed and latched,the gasket 28 effecting a water-tight seal between the door and theopening to the dishwashing chamber. A conventional timer mechanism 58may then cause a predetermined quantity of water or cleaning fluid to beadmitted to sump 29 through any suitable water filling device (notshown). The timer may then energize the pump 38 for circulating the hotfluid from the sump through the conduit 44) to the spray tube 30 fromwhence it is forcefully ejected over the surfaces of the dishes 46. Atthe conclusion of this dishwashing or jet scrubbing portion of thecycle, the solenoid 52 is energized to open a drain valve 54 and thepump 38 removes the soiled washing fluid from the sump to drain. Sincethe applicants invention pertains to a dishwasher wherein the completedishwashing cycle is accomplished in a closed chamber, the heater 50 maythen be energized to raise the temperatures within the dishwashingchamber 18, thereby to initiate a drying operation. At substantially thesame time, motor 94 is energized to initiate the condensing feature ofthis invention. Impeller 104 will cause the moisture-laden vapor to bewithdrawn from the dishwashing chamber 18 into the condenser 60. Withinthe condenser the walls of duct 74 and the heat transfer fins 76 and 9%are below the dew-point of the circulating vapor due to the flowthereacross of cooling outside air in duct 84.. Moisture will thuscondense from the circulating Vapor and will fall by gravity to thelower wall 80 of duct 74. This condensate will flow into the chamber 18and consequently into sump 20 where it may be removed to drain by theaction of a continuously operating pump 38. Of course, the pump 33 neednot be operating throughout the drying cycle and the condensate may bepermitted to collect in the sump or run by gravity to drain. 1

It should now be seen that a novel condensing system has been providedfor a dishwasher which will effect a rapid drying operation without theneed for exhausting moisture-laden vapor or steam on the surfacessurrounding the dishwasher. Furthermore, the outside air utilized todehumidify the dishwashing vapor and expedite drying is never permitted:to come in contact with the sanitized dishes.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A dishwasher including fixed top, bottom, rear and side wallsenclosing a dishwashing chamber, a generally hollow door formingsubstantially the entire front wall and closable for enclosing thedishwashing chamber, a substantially horizontal spray tube rotatableabout a horizontal axis and extending forwardly from and substantiallyperpendicular to the rear wall, means for supporting dishes above andbelow said spray tube, said bottom wall forming a sump below saidsupport means and having a sump opening selectively connected .to adrain,

means connected to said sump opening for supplying cleansing fluid tosaid spray tube for spraying said dishes in said support means wherebyfluid sprayed on said dishes gravitationally returns to said sump,heating means for drying the dishes with said door closed by vaporizingthe .fluid on said dishes after the dishes have been sprayed, said doorcomprising a front panel, a rear panel in parallel spaced relationshipto said front panel and overlying said sump, a bottom panel and a fluidvapor condenser between said front and rear panels, means between saiddoor and said chamber walls for sealing the inside of said chamber fromthe outside of said chamber, said condenser including a vapor conduitand an outside air duct partially enclosing said vapor conduitand intransverse counterfiow relationship to said vapor conduit, a

first set of heat transfer fins in said vapor conduit, a second set ofheat transfer fins in said outside air duct in engagement with saidvapor conduit and in transverse relationship to said first set, saidvapor conduit extending 'vertically in said door andhaving an inletopening in said rear panel connected on one side of said sealing meansto said chamber near the top of said chamber and an outlet opening insaid rear panel connected on said one side of said sealing means to saidchamber above said sump and below saidinlet opening to permit gravitydrainage of condensate from said vapor conduit to said sump forselective distribution to drain, said outside'air duct having an outsideair inlet and an outside air outlet in said bottom panel of said door onthe other side of said sealing means, said vapor conduit and saidoutside air duct having juxtaposed wall portions, a first impeller insaid vapor conduit on one side of said juxtaposed wall portions, asecond impeller in said outside air duct on the other side of saidjuxtaposed wall portions, and a single prime mover in said door betweensaid front and rear panels having a shaft extending through saidjuxtaposed wall portions and operable with said heating means foractuating said first impeller in said vapor conduit for initiating acirculation of fiuid vapor between said chamber and said vapor conduitfrom said inlet open ing to said outlet opening to vaporize fluid fromsaid dishes and for actuating said second impeller in said outside a-irduct for initiating a circulation of outside air between the atmosphereand said outside air duct from said outside air inlet to said outsideair outlet for condensing moisture from said fluid vapor, whereby therelative humidity of said =fiuid vapor is decreased and the drying ofsaid dishes is expedited.

2. A dishwasher including walls enclosing a dishwashing chamber anddefining an access opening, a generally hollow door formingsubstantially one entire wall and closable for enclosing the dishwashingchamber, means for spraying in said chamber, means for supporting dishesin exposed relationship to said spray means, one of said walls forming asump below said support means and having a sump opening selectivelyconnected to a drain, means connected to said sump opening for supplyingcleansing fluid to said spray means for spraying said dishes in saidsupport means whereby fluid sprayed on said dishes gravitationallyreturns to said sump, heating means for drying the dishes with said doorclosed by vaporizing the fluid on said dishes after the dishes have beensprayed, said door comprising an outer panel, an inner panel in parallelspaced relationship to said outer panel and overlying said sump, anintermediate panel interposed between said panels along one edge thereofand a fiuid vapor condenser between said outer and inner panels, meansbetween said door and said chamber walls for sealing the inside of saidchamber from the outside of said chamber, said condenser including avapor conduit and an outside air duct partially enclosing said vaporconduit and in transverse counterflow relationship to said vaporconduit, a first set of heat transfer fins in said vapor conduit, asecond set of heat transfer fins in said outside air duct in engagementwith said vapor conduit and in transverse relationship to said firstset, said vapor conduit extending through said door and having an inletopening in said inner panel connected on one side of said sealing meansto said chamber near the top of said chamber and an outlet opening insaid inner panel connected on said one side of said sealing means tosaid chamber above said sump and in gravity flow relationship to saidinlet opening to permit gravity drainage of condensate from said vaporconduit to said sump for selective distribution to drain, said outsideair duct having an outside air inlet and an outside air outlet in saidintermediate panel of said door on the other side of said sealing means,said vapor conduit and said outside air duct having juxtaposed wallportions, a first impeller in said vapor conduit on one side of saidjuxtaposed wall portions, a second impeller in said outside air duct onthe other side of said juxtaposed wall portions, and a single primemover in said door between said outer and inner panels having a shaftextending through said juxtaposed Wall portions and operable with saidheating means for actuating said first impeller in said vapor conduitfor initiating a circulation of fluid vapor between said chamher andsaid vapor conduit from said inlet opening to said outlet opening tovaporize fluid from said dishes and for actuating said second impellerin said outside air duct for initiating a circulation of outside airbetween the atmosphere and said outside air duct from said outside airinlet to said outside air outlet for condensing moisture from said fluidvapor, whereby the relative humidity of said fluid vapor is decreasedand the drying of said dishes is expedited.

References Cited in the file of this patent UNITED STATES PATENTS2,105,692 Hunicke Jan. 18, 1938 2,596,622 Vannerus May 13, 19522,607,209 Constantine Aug. 19, 1952 2,675,628 ONeil Apr. 20, 19542,716,289. Lauck Aug. 30, 1955 2,717,320 Shoulders et a1 Sept. 6, 19552,859,755 Burke Nov. 11, 1958 2,918,068 Karig Dec. 22, 1959

